Chapter 9 Questions fully solved 2023/2024 already passed

Chapter 9 Questions Explain the difference between a confined and an unconfined aquifer - correct answer An unconfined aquifer is an aquifer where water can easily flow in and out. A confined aquifer has an impermeable, or confining, layer which impedes water flow to or from the aquifer What is saltwater intrusion and what causes this problem? - correct answer Saltwater intrusion occurs when saltwater mixes with freshwater and contaminates well water. It is common in coastal areas. This happens when too many wells are drilled an the water pressure is lowered allowing the saltwater to move into the aquifer. With fewer wells drilled, the water pressure from the freshwater is higher and the saltwater cannot intrude. Describe the causes and effects of a eutrophic body of water - correct answer A body of water that has too much nitrogen or phosphorus can become eutrophic. This means there is a high level of productivity. Describe the ecological benefits of freshwater wetlands - correct answer Freshwater wetlands are important because they help to control flooding, and can absorb and store excess water and release it slowly. Describe some human activities that have impacted flooding - correct answer The construction of impermeable and paved surfaces by humans has impacted flooding The surfaces do not allow water to infiltrate into the ground, This causes the water to run off into storm sewers or streams. Describe both the benefits and consequences of dams - correct answer Benefits: water for human consumption, generation of electricity, flood control and recreation. Consequences: having to displace people, flooding an area that was not flooded, interruption of the water flow that many organisms need, and loss of breeding grounds for animals such as salmon. What are the three major uses of water and what percentage of water is used for each? - correct answer 70% of water is used for irrigation of crops, 20% for industry and 10% for household use